export function watermark(settings) {
    //默认设置
    let defaultSettings = {
        watermark_txt: 'text',
        watermark_x: 20, //水印起始位置x轴坐标
        watermark_y: 20, //水印起始位置Y轴坐标
        watermark_rows: 20, //水印行数
        watermark_cols: 20, //水印列数
        watermark_x_space: 100, //水印x轴间隔
        watermark_y_space: 50, //水印y轴间隔
        watermark_color: '#aaa', //水印字体颜色
        watermark_alpha: 0.4, //水印透明度
        watermark_fontsize: '15px', //水印字体大小
        watermark_font: '微软雅黑', //水印字体
        watermark_width: 210, //水印宽度
        watermark_height: 80, //水印长度
        watermark_angle: 15//水印倾斜度数
    };

    Object.assign(defaultSettings, settings);

    let oTemp = document.createDocumentFragment();

    //获取页面最大宽度
    let p_width = Math.max(document.body.scrollWidth, document.body.clientWidth);
    let cutWidth = p_width * 0.0150;
    let page_width = p_width - cutWidth;
    //获取页面最大高度
    let page_height = Math.max(document.body.scrollHeight, document.body.clientHeight) + 450;
    // let page_height = document.body.scrollHeight+document.body.scrollTop;
    //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
    if (defaultSettings.watermark_cols === 0 || (parseInt(defaultSettings.watermark_x + defaultSettings.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1)) > page_width)) {
        defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + defaultSettings.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space));
        defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x - defaultSettings.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));
    }
    //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
    if (defaultSettings.watermark_rows === 0 || (parseInt(defaultSettings.watermark_y + defaultSettings.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1)) > page_height)) {
        defaultSettings.watermark_rows = parseInt((defaultSettings.watermark_y_space + page_height - defaultSettings.watermark_y) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));
        defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y) - defaultSettings.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));
    }
    let x;
    let y;
    for (let i = 0; i < defaultSettings.watermark_rows; i++) {
        y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;
        for (let j = 0; j < defaultSettings.watermark_cols; j++) {
            x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;

            let mask_div = document.createElement('div');
            mask_div.id = 'mask_div' + i + j;
            mask_div.className = 'mask_div';
            ///三个节点
            let div0 = document.createElement('div');
            div0.appendChild(document.createTextNode(defaultSettings.watermark_txt0));
            let div1 = document.createElement('div');
            div1.appendChild(document.createTextNode(defaultSettings.watermark_txt1));
            let div2 = document.createElement('div');
            div2.appendChild(document.createTextNode(defaultSettings.watermark_txt2));
            defaultSettings.watermark_txt0 && mask_div.appendChild(div0);
            defaultSettings.watermark_txt1 && mask_div.appendChild(div1);
            defaultSettings.watermark_txt2 && mask_div.appendChild(div2);
            // mask_div.appendChild(document.createTextNode(defaultSettings.watermark_txt));
            //设置水印div倾斜显示
            mask_div.style.webkitTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
            mask_div.style.MozTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
            mask_div.style.msTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
            mask_div.style.OTransform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
            mask_div.style.transform = 'rotate(-' + defaultSettings.watermark_angle + 'deg)';
            mask_div.style.visibility = '';
            mask_div.style.position = 'absolute';
            mask_div.style.left = x + 'px';
            mask_div.style.top = y + 'px';
            mask_div.style.overflow = 'hidden';
            mask_div.style.zIndex = '9999';
            mask_div.style.pointerEvents = 'none';//pointer-events:none  让水印不遮挡页面的点击事件
            mask_div.style.opacity = defaultSettings.watermark_alpha;
            mask_div.style.fontSize = defaultSettings.watermark_fontsize;
            mask_div.style.fontFamily = defaultSettings.watermark_font;
            mask_div.style.color = defaultSettings.watermark_color;
            mask_div.style.textAlign = 'center';
            mask_div.style.width = defaultSettings.watermark_width + 'px';
            mask_div.style.height = defaultSettings.watermark_height + 'px';
            mask_div.style.display = 'block';
            oTemp.appendChild(mask_div);
        }
    }
    document.body.appendChild(oTemp);
}